Lunar highland melt rocks - Chemistry, petrology and silicate mineralogy

摘要: A selected suite containing several of the largest samples lunar highland melt rocks includes impact specimens (anorthositic gabbro, low-K Fra Mauro) and volcanic (intermediate-K Mauro). Although previous assumptions LKFM volcanism have fallen into disfavor, no fatal arguments against this hypothesis been presented, evidence a possibly 'inherited igneous' olivine-plagioclase cosaturation provides cause for keeping viable. Comparisons silicate mineralogy with rock compositions provide information on specimen's composition cooling history. Plagioclase-rock can be matched to experimentally determined equilibria appropriate identify refractory anorthitic clasts. Olivine-rock indicate that vitrophyres precipitate anomalously Fe-rich olivine; anomaly is not immediately evident. The Al-Ti Ca-Fe-Mg zonation in pyroxene relative rates rocks, but Cr- Al-content (where Al-rich low-Ca cores are preserved rapidly cooled samples) correlated host rock.